JP3028920B2 - Wireless telephone - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio telephone, and more particularly, to a radio telephone having a function of generating a warning sound indicating deterioration of communication line quality.

[0002]

2. Description of the Related Art In this type of conventional radio telephone,
As shown in FIG. 6, when the quality of the wireless communication line connecting the wireless telephone 100 and the base station 101 for connecting the communication from the wireless telephone to the communication line is deteriorated, an alarm sound is generated and the caller is notified. Some have the function of notifying the user. An example of a wireless telephone having such a function is disclosed in
No. 182129.

In this case, the volume of a warning sound indicating deterioration of the quality of a communication line and the like are fixedly set in advance irrespective of the level of the voice of the other party. In addition, it is fixedly determined regardless of the degree of the quality deterioration.

FIG. 7 shows the configuration of a digital radio telephone having this kind of alarm sound transmission function. From the radio wave received by the antenna 1, only the radio wave of the reception frequency is extracted by the reception filter 2 and sent to the radio reception unit 3. The detection is performed in the wireless receiving unit 3 and demodulated into digital data. The demodulated received data is sent to the modem 4 and separated into voice data and control data by the reception processing unit 5 in the modem.

[0005] Generally, received voice data is error-correction-coded in order to correct, at the time of reception, data errors that occur when the voice data propagates in the air by radio waves.
Error correction is performed by the error correction reception processing unit 7 of the error correction unit 6. The error rate at the time of this error correction is detected,
This error rate is sent to the control unit 10.

[0006] The received decoded data which has been subjected to the high-efficiency speech coding after the error correction is supplied to a speech decoder 8 and decoded.
After the PCM data is obtained by digitizing the sound amplitude, D / A
The signal is converted into an electric amplitude signal by the converter 9 and the mixer 12
The signal is supplied to the speaker 14 via the amplifier 13 and is converted into the received voice.

The control unit 10 comprises a microprocessor for performing various controls of the wireless telephone. This control unit 10
Determines the line quality from the error rate of the received data received from the error correction unit 6 and supplies the line quality information to the transmission processing unit 20 of the modem 4. In the transmission processing unit 20, this line quality information is subjected to transmission processing and incorporated into transmission data.

[0008] Further, the control unit 10 receives a ring tone, a key operation sound,
It controls the types of warning sounds such as line quality warning sounds, etc., and their generation and stop. Upon receiving an instruction to generate a warning sound from the control unit 10, the warning sound generation unit 11 generates a warning sound according to the instruction and sends it to the mixer 12. Therefore, this warning sound is superimposed on the received voice.

The transmitted voice is converted into an audio signal as an electrical amplitude signal by the microphone 15, amplified by the amplifier 16, and converted into PCM data by the A / D converter 17. The PCM data is subjected to high-efficiency voice coding by the voice encoder 18 and the error correction transmission processing unit 1 of the error correction unit 6.
At 9, it is converted into an error code such as a convolutional code.

The transmission voice converted into the error correction code is transmitted to the modem 4, and is combined with control information such as line quality information from the control unit 10 in the transmission processing unit 20 and arranged in a signal format for transmission. A changing transmission process is performed.
The transmission voice in the transmission signal format is digitally modulated by the radio transmission unit 21 together with the control information, and transmitted as a transmission radio wave from the antenna 1 via the transmission filter 22.

The transmission filter 22 allows the signal transmitted from the radio transmission unit 21 to pass therethrough, but does not allow the signal received by the antenna 1 to pass through the radio transmission unit 21 and also transmits the signal of an unnecessary frequency during transmission. Also suppresses.

The display unit 26 receives display data from the control unit 10 and displays a telephone number or the like at the time of dialing. The volume adjustment of the received voice can be performed by operating the volume adjustment key 25 of the key input unit 23. The key input unit 23 includes a dial key and the volume adjustment key 25,
Various keys are provided, and when these keys are pressed, the control unit 10 electrically detects them.

The control unit 10 controls the change of the received sound volume by increasing or decreasing the amplification factor of the amplifier in response to the operation of pressing the volume adjustment key 25. Further, the volume of the warning sound can be controlled by adjusting a volume (not shown) provided in the warning sound generating unit 11. Once the volume of this warning sound is set with the volume, it will be fixed to that set value thereafter.
The volume of the warning sound transmitted from the speaker 14 is determined by the volume and the amplification factor of the amplifier.

For this reason, when the received sound volume is increased or decreased by operating the volume adjustment key 25, the warning sound also increases or decreases at the same time, but the warning volume does not change with respect to the volume of the other party's sound. When the volume is small and it is difficult to hear, the other party's voice can be heard at an appropriate volume by increasing the reception volume by operating the volume adjustment key 25, but the warning volume also increases accordingly.

If the warning sound is generated during a call, even if the other party's voice is loud, the warning sound has a volume that does not hinder the call, but if the other party's voice is low, the warning volume is the same. The call may be hindered, for example, the voice of the other party may not be heard easily.

In this case, if the volume is reduced by the volume adjustment key 25, the sound from the speaker 14 will not only be reduced to a warning sound but also to the other party's voice because the amplification factor of the amplifier 13 changes. Conversely, even if the volume is increased by the volume adjustment key 25, not only the other party's voice but also the warning sound will increase in proportion to it, so if the other party's voice is low, the warning sound will not disturb the call. There is no change.

[0017]

In this type of conventional device, the volume of the warning sound during a call is fixedly set regardless of the volume of the other party's voice. When the surroundings are noisy or the voice is loud, it is difficult to notice. When the volume of the warning sound is high, there is a problem in that if the voice of the other party is low, the conversation is hindered.

Further, in this type of conventional radio telephone, since the volume, tone and repetition period of the alarm sound are fixed irrespective of the degree of quality deterioration of the communication line, the degree of quality deterioration cannot be determined at all. There are also problems.

For example, when talking while moving,
There is a drawback in that it is not possible to judge whether a call is likely to be interrupted immediately or a temporary deterioration of the line state when the warning sound of the line quality deterioration sounds. Therefore, when the deterioration progresses rapidly and a warning sound is sounded, the call is cut off in a shorter time than the time expected by the user until the call is cut off, and a situation occurs in which the call is cut off during the conversation.

[0020] Further, since the warning sound of the deterioration of the line quality sounds, even if the user intends to move to a place where the condition of the radio line is considered to be good, the user may move in a bad direction and the call may be disconnected.

An object of the present invention is to provide a radio telephone capable of sounding a warning sound of an appropriate volume in accordance with the surrounding noise and voice volume of a partner.

Another object of the present invention is to provide a radio telephone capable of freely controlling the volume, tone, repetition period and the like of a warning sound in accordance with the degree of quality deterioration of a communication line.

[0023]

A digital radio telephone, comprising: means for generating a warning sound indicating deterioration of the quality of a communication line; volume detection means for detecting a volume of a received voice;
Look including a warning sound control means for controlling the transmission level of the alarm sound in response to the volume of the received voice, the alarm sound control means
Transmits the warning sound when the volume of the received voice is high.
When the output level is increased and the volume of the received voice is low
The transmission level of the warning sound is reduced .

[0024] The digital radiotelephone communicates with a voice coding system including a parameter representing a voice amplitude, and the volume detecting means is configured to detect a volume of the received voice based on the parameter. It is characterized by having.

Another radiotelephone according to the present invention is a digital radiotelephone having a function of generating a warning sound indicating deterioration of the quality of a communication line, wherein the deterioration of the communication line is progressing rapidly or slowly. A warning sound control means for changing and controlling the warning sound according to the degree of progress is provided.

The warning sound control means includes at least one of a volume, a tone, and a repetition period of the warning sound.
One is characterized by controlling one.

[0027]

The above-mentioned object is achieved by controlling the volume of a warning sound in accordance with the volume of a received voice and controlling at least one of the volume, tone and repetition period of the warning sound in accordance with the degree of quality deterioration of a communication line. Can be achieved.

[0028]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of an embodiment of the present invention, and the same parts as those in FIG. 6 are denoted by the same reference numerals. In the present embodiment, the volume of the warning sound can be automatically changed by controlling the volume (VR) 24 of the warning sound generating unit 11 under the control of the control unit 10.

The control unit 10 detects the volume of the received voice according to the received decoded data sent from the error correction reception processing unit 7 of the error correction unit 6, and variably controls the volume 24 according to the volume of the received voice. Then, the automatic volume adjustment of the warning sound is appropriately performed.

Here, a specific example of the error correction reception processing section 7 will be described with reference to FIG. The reception data 30 is audio data that has been subjected to error correction coding.
Are decoded by an error correction decoding unit 32 to become received decoded data 31. This decoded data 31 is used for the audio decoder 8 in FIG.
And at the same time, error-correction-encoded by an error-correction encoding unit 35 again to become coded data 36.

Since the received decoded data 31 is data after error correction, if the error is completely corrected by the error correction code, the received decoded data 31 becomes error-free received data. If the received decoded data 31 that is the error-free received data is error-correction-encoded again, it becomes error-free corrected encoded reception data, which is the code data 36.

The error rate 33 of the received data 30 is calculated by comparing the actually received data 30 and the code data 36, which is error-free received data, with a comparator 34 and calculating the ratio of different data. Can be calculated. This error rate is sent to the control unit 10 as line quality information indicating the quality of the line.

The data received from the antenna 1 is sent to the modem 4 and separated into voice data and control data by the reception processing unit 5 therein. The audio data is sent to the error correction reception processing section 7 shown in FIG. 2 in the error correction section 6, subjected to error correction processing, and sent to the audio decoder 8.

Here, the voice data is generally subjected to high-efficiency voice coding, and the coding method will be described with reference to FIG. In a high-efficiency audio coding digital wireless telephone, generation of an audio signal can be approximately represented by a digital model as shown in FIG. The vocal cords 40 can be modeled as a sound source 42, and the vocal tract 41 can be modeled as a synthesis filter 46.

As a sound source 42, an impulse train located at a position separated by a pitch period is used in the case of a voiced sound, and a noise source is used in the case of a non-voiced sound.
3 and the noise generator 44 become the sound source 42.

On the other hand, the characteristics of the vocal tract 41 are modeled by a synthesis filter 46 configured using a digital filter. The sound generated by such a digital model is represented by a sound source 42, a sound source amplitude 45, and a synthesis filter 46.

In a digital communication type radio telephone using a high-efficiency audio coding system, the type of the sound source, the pitch period, the amplitude of the sound source signal, and the coefficient of the synthesis filter are predicted for the input voice signal, and the results are calculated. Are transmitted to the other party, and the receiving side synthesizes the original voice from these parameters to transmit the voice with less information.

Referring again to FIG. 1 and FIG. 2, the audio data is converted into an audio code by an error correction reception processing unit 7 in the error correction unit 6, and the error correction unit 6 The control unit 1 controls a parameter representing the amplitude of the voice in the code.
0. In FIG. 2, the received decrypted data 3
1 includes a parameter representing the amplitude of this sound,
This parameter is sent to the control unit 10.

The control unit 10 detects the volume of the received voice with reference to the parameter indicating the voice amplitude, and adjusts the volume of the warning sound generating unit 11 by variably controlling the volume 24 according to the detected volume. is there. More specifically, the volume of the received voice is determined from the parameter value indicating the amplitude of the voice and the volume 24 is operated by operating the volume 24 to increase the volume of the warning sound when the volume of the received voice is large, and to decrease the volume of the warning sound when the volume of the received voice is small. The volume is reduced so that a warning sound is transmitted from the speaker 14 at a volume appropriate for the received voice.

As a parameter indicating the amplitude of the speech in the high-efficiency speech code, VSELP (Vector Sum Exited Linear Predictio), which is a coding system currently used in full-rate digital car telephone systems in Japan and North America, is used.
In the n) method, the RO parameter indicating the frame energy corresponds to this. In addition, P is a code system used for a Japanese half-rate digital car telephone system.
SI-CELP (Pitch Synchronous Innovation Code-
In the CELP: Code Exited Linear Prediction (CELP) method, a POW parameter which is a power parameter corresponds to this.

The parameters representing the amplitude of the speech in the high-efficiency speech coding will be described below in detail. VSELP
In the method, the frame energy is calculated as a root mean square R (0) of the input speech sample S (n) as shown in FIG. 4A, and then converted to a decibel value RdB. After that, it is converted into an RO code (parameter) corresponding to each level.

The respective equations will be shown specifically. First, R (0)
Is as follows: R (0) = {S (n) S (n) + {S (n-10) S (n-10) / 320} (1) Here, Σ indicates the sum of n = 10 to 169. When this equation (1) is shown in the figure, it is expressed as an average value of the squares of the voice input sample values in the section as shown in FIG.

Using R (0) in the equation (1), RdB is as follows: RdB = 10 log ₁₀ (R (0) / Rmax) (2) Rmax indicates the square of the maximum value of the sample amplitude.
The 32 quantization value of RdB is from the minimum value -66 to the maximum value-
It takes a value up to 4 and corresponds to the 0 to 31 codes of RO.

RO is obtained as an RO in which abs {RO− (RdB + 66) / 2} (3) is minimized. Note that abs indicates an absolute value.

When using the VSELP-type speech code, the control unit 10 determines the reception volume with reference to the value of the RO parameter taking the value of 0 to 31. still,
As for the amplitude of the voice, the RO parameter 0 is the minimum, and 31 is the maximum.

Next, a method of calculating the power parameter index POW in the PSI-CELP system will be described below. A 20 msec audio frame consists of four 5 msec
, And the average amplitude amp _n (n = 0, 1, 2, 3) of each sub-frame is given by: amp _n = {S ² (i) / NSUB} ^1/2
... It is obtained by (4).

Where Σ is i = NSUBn to NSUBn + NSUB
NSUB is a subframe length = 80, and S (i) is an input signal after preprocessing. S (i) indicates an input signal to the encoder after preprocessing such as a prefilter has been completed.

Further, this is μlaw-converted to obtain μamp _n = ｛log ₁₀ (1.0 + μamp _n / Smax) / log ₁₀ (1.0 + μ) (5), where μ = 100 and Smax are input. Indicates the maximum amplitude of the PCM signal.

Then, i at which err = {μamp _n −Cpow (i, n)} ² (6) becomes the minimum is the power parameter index POW. Σ is the sum of n = 0 to 3, and Cpow (i,
n) is obtained from a power quantization table that defines the values for the indexes i and n, and takes an integer from i = 0 to 127.

The warning sound is controlled to be changed according to the amplitude by referring to the parameter representing the amplitude of the received voice. In this case, parameters of 10 to 20 voice samples are averaged. If the warning sound volume is controlled in accordance with the average value, it becomes more realistic.

The case where the volume of the warning sound is controlled in accordance with the volume of the received voice has been described above. However, an embodiment in which the volume and tone of the warning sound, the repetition period thereof, and the like are controlled in accordance with the degree of the communication line quality. Will be described. In the case of a digital radio telephone, the configuration is the same as that shown in FIG. 1, and the state of deterioration of the communication line quality can be determined from the error rate 33 in FIG. The degree of deterioration is known.

The quality level indicating the line quality is notified to the base station via the modem 4 and the radio transmission unit 21. The base station determines the quality based on the notified line quality level and if the current state continues. When it is determined that there is a possibility that the call may be interrupted, the wireless telephone is notified to emit a line quality deterioration warning sound as necessary.

The control unit 10 needs to transmit a line quality deterioration warning sound from the base station in the control data, or need to transmit the line quality deterioration warning sound from the error detection result and error rate from the error correction unit 6. When it is determined that this is the case, the warning sound generation unit 11 is instructed to that effect.

At this time, based on the error detection result and error rate from the error correction unit 6, the control unit 10 is proceeding in a direction in which the channel quality is degraded, is progressing in a direction in which it is improved, or is proceeding rapidly. Or slow progress. The control unit 10 determines the volume, timbre, and transmission cycle of the warning sound according to the determination result, and
To instruct.

For example, when the line quality deteriorates rapidly, the control unit 10 sets the tone of the warning sound to be conspicuous, and gives an instruction to increase the volume and shorten the transmission cycle. It sends out a warning sound that makes you feel tense. Also, when the line quality deteriorates moderately and the recovery is in progress, the tone of the warning sound is made to be softer, and instructions such as lowering the volume and lengthening the transmission cycle are issued to give a mild atmosphere. Sound.

FIG. 5 is a block diagram of an embodiment of the present invention, which is an example in the case of an analog wireless telephone. The reception signal received by the wireless reception unit 51 is demodulated by the demodulation unit 53 and separated into a control signal and a voice signal. Further, the received electric field strength of the received signal is measured by the electric field detection unit 52,
The measurement result is sent to the control unit 54.

The control section 54 notifies the base station of the received electric field strength via a transmitting section (not shown), and the base station judges the line quality from the notified received electric field strength, and Notifies the wireless telephone to sound a warning sound as necessary. The control unit 54 needs to transmit a line quality deterioration warning sound from the base station in the control signal from the demodulation unit 53 or to transmit a line quality deterioration warning sound from the electric field detection result from the electric field detection unit 52. When it is determined that there is
The warning sound generation unit 55 is instructed to that effect.

In this case as well, the control unit 54 determines the degree of deterioration of the line quality, the degree of progress, the speed, etc., as in the case of the above digital system, and according to the result, the volume, tone color, Determining the repetition period and instructing the warning sound generation unit 55 is the same as in the digital case.

In FIG. 5, reference numeral 56 denotes a mixer for mixing the received voice and the warning sound, 57 denotes an amplifier for amplifying the output of the mixer, and 58 denotes a speaker.

As examples of the control of the alarm sound, various examples other than the above-described control mode are conceivable. In short, at least one of the volume, the tone color, and the repetition period is determined according to the degree of deterioration of the line quality. What is necessary is just to control according to it.

[0062]

As described above, according to the present invention, the volume of the line quality deterioration warning sound is controlled in accordance with the reception volume, so that the warning sound has an appropriate volume with respect to the reception voice. Thus, there is an effect that the warning sound does not interfere with the call or is too loud to be recognized because of the voice of the other party. In addition, the use of a parameter representing the frame energy of the received speech code for the detection of the received sound volume has the effect of eliminating the need for a speech level detection circuit.

Further, the volume, tone and repetition period of the warning sound are controlled in accordance with the degree of the line quality.
The user can easily and clearly judge the degree of deterioration of the line quality, and if the situation falls into a bad line quality such that a warning sound sounds, the user tries to move to a place with good line quality and conversely moves to a bad place. This has the effect of making it easier to find places with good line quality.

Further, when a call is in progress while moving, it is possible to judge how quickly the line quality is deteriorating and the alarm is sounding, and how fast the deterioration is progressing. In such a case, there is an effect that it is possible to predict how long the interruption will occur.

[Brief description of the drawings]

FIG. 1 is a block diagram of one embodiment of the present invention.

FIG. 2 is a block diagram illustrating an example of an error correction reception processing unit 7 in FIG. 1;

FIG. 3 is a diagram for explaining a digital model of voice generation.

FIG. 4A is a diagram showing R in the VSELP speech coding system;
FIG. 4B is a diagram illustrating a generation process of an O-code (parameter), and FIG. 4B is a diagram illustrating a form of a root mean square of a voice input sample.

FIG. 5 is a block diagram of another embodiment of the present invention.

FIG. 6 is a diagram showing a relationship between a wireless telephone and a base station.

FIG. 7 is a block diagram showing an example of a conventional digital wireless telephone.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 antenna 2 reception filter 3 wireless reception unit 4 modem 5 reception processing unit 6 error correction unit 7 error correction reception processing unit 8 audio decoder 9 D / A converter 10 control unit 11 warning sound generation unit 12 mixer 13, 16 amplifier 14 speaker Reference Signs List 15 microphone 17 A / D converter 18 audio encoder 19 error correction transmission processing unit 20 transmission processing unit 21 wireless transmission unit 22 transmission filter 23 key input unit 24 volume 25 volume adjustment key

Claims (7)

(57) [Claims] 1. A digital wireless telephone, comprising: means for generating a warning sound indicating quality degradation of a communication line; volume detecting means for detecting a volume of a received voice; Warning sound output level
Warning sound control means for controllingSee The warning sound control means is provided when the volume of the received voice is high.
In this case, the output level of the warning sound is increased,
When the volume of the sound is low, the output level of the warning sound is reduced.
Do A wireless telephone characterized by the above. 2. A digital wireless telephone which performs communication by a voice coding method including a parameter representing a voice amplitude, wherein said volume detecting means is configured to detect a volume of said received voice based on said parameter. The wireless telephone according to claim 1, wherein: 3. The wireless telephone according to claim 2, wherein said volume detection means is configured to detect a volume of said received voice according to an average value of a plurality of continuous samples of said parameter. . 4. A digital radiotelephone having a function of generating a warning sound indicating quality deterioration of a communication line, wherein the degree of quality deterioration of the communication line is rapidly progressing or slowly progressing. A wireless telephone, comprising: a warning sound control unit for changing and controlling the warning sound in response to the change. 5. The wireless telephone according to claim 4, wherein the warning sound control means controls at least one of a volume, a tone, and a repetition period of the warning sound. 6. The apparatus according to claim 4, wherein the warning sound control means is configured to determine a degree of quality deterioration of the communication line in accordance with a result of error detection of received data.
Or the wireless telephone according to 5. 7. The wireless telephone according to claim 4, wherein said alarm sound control means is configured to determine a degree of quality deterioration of said communication line according to a received electric field level.